The project on the effects of retinoic acids on brain, behavior and drug interactions investigates the pathophysiology of retinoic acid action in vivo. Rats are the current model but expansion into mouse and guinea pig models is anticipated. The primary focus of the rat model is the assay of the pharmacokinetics of the interaction of 13-cis-retinoic acid with neuroleptics. Early results have shown statistically significant changes in the blood levels of haloperidol and one of its metabolites after the concurrent administration of 13-cis-retinoic acid to rats.